Characteristics of viruses

Statement 1 is correct: Viruses lack metabolic enzymes and cannot generate their own energy (ATP). They are obligate intracellular parasites. Statement 2 is incorrect: Viruses cannot be cultured in synthetic media; they require living host cells (tissue culture, embryos, or animal hosts) because they depend on host cellular machinery for replication. Statement 3 is incorrect: Viruses can be transmitted through both biological vectors (like mosquitoes for dengue) and non-biological means (like direct contact, contaminated surfaces, or air droplets). Many viruses do not require biological vectors for transmission. > Viral Characteristics: Viruses are obligate parasites lacking independent metabolism and requiring living host cells for replication; transmission can occur via multiple routes beyond biological vectors. Answer: (a).